Welcome, Danny.
Oh… have I been there before! I would go to sleep thinking about how if I only started from scratch with everything I now know…
Luckily I’m too lazy.
The solution was inevitably obvious. That’s where the helpful gals and guys of the forum come in.
I’m kinda modifying as I go, but it’s looking Very messy!
This is the way.
I wouldn’t fret too much about this part because there is little penalty for adapting the database. When I want to delete a database thing or field but I’m not sure, I put it in “purgatory” by adding zzz_ before its name. This will tell futureMe that pastMe thought about getting ride of that.
About what you need in the database, the best way is to try to put on your user’s hat and try the app as much as possible. Thinking like the user will help you find the missing parts.
Otherwise, Petter has a great guide on all things database and performance.
On how to draw a database, I’m a 
pen+paper → Miro type of person.
For responsiveness, I’ve been summarizing some of my findings (I’ve never really bothered with it before). The tl;dr on that is “Bubble doesn’t give you a structure, you have to create one yourself.”
I can’t seem to click on this button and have the thing needed ( bed in this case ) and then reference that thing ??
You know you can make many things clickable, not just a button, right?
How is that user browsing donations wanted? I’m assuming that there is a page with an repeating group, right? Why can’t you just click something within that RG to start the workflow you have in mind?